Biosignal-based avatar control system and method

ABSTRACT

A biosignal-based avatar control system according to an embodiment of the present disclosure includes an avatar generating unit that generates a user&#39;s avatar in a virtual reality environment, a biosignal measuring unit that measures the user&#39;s biosignal using a sensor, a command determining unit that determines the user&#39;s command based on the measured biosignal, an avatar control unit that controls the avatar to perform the command, an output unit that outputs an image of the avatar in real-time, and a protocol generating unit for generating a protocol that provides predetermined tasks, and determines if the avatar performed the predetermined tasks. According to an embodiment of the present disclosure, it is possible to provide feedback in real-time by understanding the user&#39;s intention through analysis of biosignals and controlling the user&#39;s avatar in a virtual reality environment, thereby improving the user&#39;s brain function and motor function.

DESCRIPTION OF GOVERNMENT-FUNDED RESEARCH AND DEVELOPMENT

Institute for Information & Communications Technology Promotion (IITP)grant funded by the Korea government (MSIT) (2017-0-00432, Developmentof non-invasive integrated BCI SW platform to control home appliance andexternal devices by user's thought via AR/VR interface)

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2019-0102367, filed on Aug. 21, 2019, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which in its entiretyare herein incorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a biosignal-based avatar controlsystem and method, and more particularly, to a system and method thatunderstand a user's intention by measuring and analyzing biosignals suchas electroencephalography (EEG), electromyogram (EMG) andelectrooculogram (EOG) signals, and control the user's avatar in avirtual reality environment based on the user's intention, therebyproviding feedback in real-time.

2. Description of the Related Art

Recently, technologies that control electronic devices or exoskeletonrobots using human biosignals are being intensively studied. Among them,brain-computer interface (BCI) measures a user's brainwave throughelectroencephalography (EEG) and generates a control signalcorresponding to the brainwave to control a device, and it can be usedin various industrial fields, for example, cognition related research,motor rehabilitation, exoskeleton robots or electric wheelchairs forpatients paralyzed in spine.

Further, with the development of BCI technology, interaction with anobject in a virtual reality environment using EEG is developed. Thevirtual reality is technology that realizes a new virtual space on acomputer and outputs it to an output device such as a monitor or ahead-mounted display, and it realizes a space in which a user canexperience many sensory phenomena including a sense of vision in avirtual situation, to provide a sense of realistic space to the user.The virtual reality provides virtual space and activities beyond thevisual and physical limitations.

More recently, there are gradually growing trends of training programsfor virtual training in a similar environment to real motion. In thecase of cognitive and motor rehabilitation programs, there are reportsabout research results that cognitive and motor abilities of patientswith neurological impairment can be improved through EEG signal-basedmotor imagery.

This is improvements in brain function and motor function using a sortof neurofeedback. The neurofeedback refers to a biofeedback techniquethat regulates behavior patterns while observing brainwaves, byinforming a patient of his/her current brainwave state, setting a targetbrainwave state and training the patent for how to regulate in order toreach the target brainwave state. This is based on the principle thatthe human mind has a self-control function of regulating in abehavioral, cognitive and physiological manner. For example, an ADHDpatient's brainwaves are measured and displayed, and in the patient'sattempts to change the brainwaves by changing his/her mental state,stimuli are displayed on the screen or sound emits, so that the patientlearns self-control by positive reinforcement, and this training may berepeatedly performed to obtain a long-term treatment effect ofneuroplasticity.

However, there are not so many developed treatment systems or trainingsystems combined with virtual reality technology and neurofeedback. Inaddition, earlier technology usually focuses only on EEG signals, andtechnology that controls avatars or objects in virtual reality using theentire biosignal including an EEG signal, or systems that can operate inan integrated manner for evaluation and training have never beenpublished.

SUMMARY

The present disclosure is directed to providing a system for evaluatinga user's biosignal characteristics or enhancing the user's biosignal, byunderstanding the user's intention through measurement and analysis ofbiosignals such as electroencephalogram (EEG), electromyogram (EMG) andelectrooculogram (EOG) signals, and controlling the user's avatar in avirtual reality environment based on the user's intention, therebyproviding feedback in real-time.

A biosignal-based avatar control system according to an embodiment ofthe present disclosure includes an avatar generating unit that generatesa user's avatar in a virtual reality environment, a biosignal measuringunit that measures the user's biosignal using a sensor, a commanddetermining unit that determines the user's command based on themeasured biosignal, an avatar control unit that controls the avatar toperform a motion corresponding to the command, an output unit thatoutputs an image of the avatar performing the motion in real-time, and aprotocol generating unit for generating a protocol that providespredetermined tasks that can be performed by controlling the avatar'smotion, and determines if the avatar performed the predetermined tasks.

In an embodiment, the protocol may include an evaluation protocol forevaluating the user's biosignal characteristics or a training protocolfor enhancing the user's biosignal.

In an embodiment, the biosignal may include at least one of anelectroencephalogram (EEG) signal, an electromyogram (EMG) signal and anelectrooculogram (EOG) signal.

In an embodiment, the speed of the motion or magnitude of rotation ofthe avatar may be controlled based on an amplitude of the biosignal.

In an embodiment, the command determining unit may process the measuredbiosignal through frequency filtering, spatial filtering, featureselection, and classification, and determine a command corresponding toa result value of the processing.

A biosignal-based avatar control method according to an embodiment isperformed by a processor, and includes generating a user's avatar in avirtual reality environment, receiving the user's biosignal from asensor, determining the user's command based on the biosignal,controlling the avatar to perform a motion corresponding to the command,outputting an image of the avatar performing the motion in real-time,and providing a protocol that provides predetermined tasks that can beperformed by controlling the avatar's motion, and determines if theavatar performed the predetermined tasks.

In an embodiment, the determining the user's command based on themeasured biosignal may include processing the measured biosignal throughfrequency filtering, spatial filtering, feature selection andclassification, and determining a command corresponding to a resultvalue of the processing.

In an embodiment, the protocol may include an evaluation protocol forevaluating the user's biosignal characteristics or a training protocolfor enhancing the user's biosignal.

In an embodiment, the biosignal may include at least one of an EEGsignal, an EMG signal and an EOG signal.

In an embodiment, the determining the user's command based on themeasured biosignal may include processing the measured biosignal throughfrequency filtering, spatial filtering, feature selection andclassification, and determining and executing a command corresponding toa result value of the processing.

In an embodiment, the speed of the motion or magnitude of rotation ofthe avatar may be controlled based on an amplitude of the biosignal.

There may be provided a computer program stored in a computer-readablerecording medium, for performing the biosignal-based avatar controlmethod according to an embodiment.

According to an embodiment of the present disclosure, it is possible toprovide feedback in real-time by understanding the user's intentionthrough measurement and analysis of biosignals such aselectroencephalogram (EEG), electromyogram (EMG) and electrooculogram(EOG) signals, and controlling the user's avatar in a virtual realityenvironment based on the user's intention.

In addition, the system according to an embodiment provides anevaluation/training protocol for evaluating the user's biosignalcharacteristics or enhancing the user's biosignal, by providingpredetermined tasks that can be performed by controlling the avatar'smovement, and determining if the avatar performed the predeterminedtasks. Through this biofeedback system, it is possible to improve theuser's brain function and motor function and obtain a long-termtreatment effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an architecture diagram showing a biosignal-based avatarcontrol system according to an embodiment.

FIG. 2 shows a signal processing process of determining a command basedon a biosignal in a biosignal-based avatar control system according toan embodiment.

FIG. 3 shows the real-time output of an image of an avatar performing amotion in a biosignal-based avatar control system according to anembodiment.

FIG. 4 is a flowchart showing a biosignal-based avatar control methodaccording to an embodiment.

DETAILED DESCRIPTION

While embodiments are hereinafter described in detail with reference tothe accompanying drawings and disclosure in the accompanying drawings,the intended scope is not limited or restricted by the embodiments.

The terms as used herein are general terms selected as those being nowused as widely as possible in consideration of functions, but they mayvary depending on the intention of those skilled in the art or theconvention or the emergence of new technology. Additionally, in certaincases, there may be terms arbitrarily selected by the applicant, and inthis case, the meaning will be described in the correspondingdescription part of the specification. Accordingly, it should be notedthat the terms used herein should be interpreted based on thesubstantial meaning of the terms and the context throughout thespecification, rather than simply the name of the terms.

Additionally, the embodiment described herein may have aspects ofentirely hardware, partly hardware, and partly software, or entirelysoftware. The term unit”, “module”, “device”, “server” or “system” usedherein refers to computer-related entity such as hardware, hardware, andsoftware in combination, or software. For example, the unit, module,device, server or system may refer to hardware that makes up a platformin part or in whole and/or software such as an application for operatingthe hardware.

Hereinafter, exemplary embodiments will be described in more detail withreference to the accompanying drawings.

A Biosignal-Based Avatar Control System

FIG. 1 is an architecture diagram showing a biosignal-based avatarcontrol system according to an embodiment. Referring to FIG. 1 , theavatar control system 10 includes an avatar generating unit 100, abiosignal measuring unit 200, a command determining unit 300, an avatarcontrol unit 400, an output unit 500 and a protocol generating unit 600.Hereinafter, the roles and functions of each element will be describedin detail.

The avatar generating unit 100 generates a user's avatar in a virtualreality environment. In the specification, the avatar refers to avirtual character that can be controlled according to the user's commandin virtual reality created as a virtual space by computer programming,not in the real world. The avatar looks like a human having a similarshape to the user to improve the user's immersion and provide smoothbiofeedback but is not limited to a specific shape.

In an embodiment, the avatar may be automatically generated based on themeasured biosignal. For example, the user's heartbeat change or facetemperature change may be detected and the avatar's facial color orexpression and pose may be changed accordingly, or the user's gazedirection or blink may be detected by measuring an electrooculogram(EOG) signal and the avatar's gaze direction may be representedaccordingly. Appropriately changing the avatar's shape or attitude in avirtual environment according to the user's biosignal may improverealism and immersion in virtual reality.

The avatar generated in the virtual reality environment performs amotion corresponding to a command determined based on the user'sbiosignal as described below. Using this, the user may control theavatar in virtual reality to perform a specific motion by sending thebiosignal without actually performing the motion, and execute anevaluation protocol or a training protocol provided by the program.

The biosignal measuring unit 200 measures the user's biosignal using asensor. In an embodiment, the biosignal may include anelectroencephalogram (EEG) signal, an electromyogram (EMG) signal, andan electrooculogram (EOG) signal, and in addition to the biosignaldescribed herein, a variety of biosignals may be measured and used.

The EEG signal is the electrical signal recording of potential generatedby the cerebral cortex and may be measured using an electrode sensorattached to the user's head. As an EEG signal is generated from aspecific part of the brain in a specific situation in which humanexperiences, an EEG signal of desired characteristics (wavelength,frequency, intensity, etc.) may be generated by applying any type ofsensory stimulus or stimulating the brain by the user's imagination, andmay be matched with a specific command and a control signal to control adevice.

The EMG signal is the electrical signal recording of action potentialgenerated by muscles and may be measured by attaching electrodes to theuser's skin surface or directly inserting a needle into the muscle. Inthe same way as the EEG signal, an EMG signal of desired characteristicsmay be generated by applying a sensory stimulus to a specific body partof the user's intentional muscle activation and may be matched with aspecific command and a control signal to control a device.

The EOG signal is the electrical signal recording of a potentialdifference caused by changes such as contraction or relaxation ofmuscles around eyes and may be measured by attaching electrodes to theuser's skin around the eyes. As a specific EOG signal is generated by aspecific eye movement, the user's eye movement may be tracked from theEOG signal measurement, and in the same way as EEG and EMG, may bematched with a specific command and a control signal to control adevice.

The command determining unit 300 receives the biosignal measured by thebiosignal measuring unit 200 and determines the user's correspondingcommand by processing the biosignal through the processor. Relatedinformation necessary to determine the command, such as an analysisalgorithm or a lookup table, may be stored in memory together with abiosignal based control program.

FIG. 2 shows a signal processing process of determining the commandbased on the biosignal in the biosignal-based avatar control systemaccording to an embodiment. Referring to FIG. 2 , the commanddetermining unit 300 may process the measured biosignal throughfrequency filtering, spatial filtering, feature selection, andclassification.

The command determining unit 300 may perform frequency filtering of thebiosignal through the processor. A low-pass filter may be used to removehigh-frequency noise, a band-pass filter may be used to select aspecific frequency domain, or a band-stop filter may be used to remove aspecific frequency domain.

The biosignal having the selected specific frequency goes throughspatial filtering. This is to maximize the feature based on the spatiallocation of the body to which the electrode for measuring biosignals isattached. A weight may be given to the specific location, i.e., thespecific electrode through spatial filtering, and through this, inrecognizing the user's specific command, a feature vector is extractedby giving a weight to the largest spatially influential part. Forexample, when the user has a certain intention, it is possible toextract a feature vector by giving a weight to a specific location(electrode) having a great change due to a high relevance to thecorresponding intention by the application of a spatial filteringalgorithm, for example, Common Average Reference (CAR), Common SpatialPattern (CSP), to the biosignal having passed through frequencyfiltering.

The command determining unit 300 extracts the feature vector based ondata power calculated including a log value and a variance value for thecorresponding frequency of the filtered signal. For example, theprocessor may quantitatively analyze a ratio of the signal component ofthe specific frequency occupied on signal data based on the fast Fouriertransform (FFT).

Besides, the feature vector may be extracted by calculating a mean, adeviation, Root mean square (RMS), skewness, kurtosis and Dominantfrequency (DF) by the application of a signal processing function to thebiosignal, and the extracted feature vector data may be used todetermine the corresponding user's command.

When pre-processing of the biosignal is completed, the commanddetermining unit 300 may generate a plurality of classifiers through aclassifier generation module. The processor may generate the classifiersbased on a plurality of classification algorithms. The plurality ofclassifiers classifies biosignal data and determines if the datacorresponds to a specific class.

A command determination module selects a motion corresponding toreal-time biosignal data from a plurality of motions based on theclassifiers, and finally, determines the user's command. In detail, theprocessor may calculate each motion for real-time input biosignal dataas output values such as probabilities or scores based on the biosignalclassifiers, select a motion having a highest probability or score, anddetermine a command.

According to embodiments, various types of commands may be pre-stored tomatch the biosignals. For example, further to a command for simplymoving the avatar forward, rearward, leftward and rightward, a commandsuch as sitting down/standing, or a joint-related movement such aslifting up and down the feet and bending or straightening the knees maybe designated as the command. As opposed to the existing gesture capturebased avatar control method, the present disclosure may simultaneouslyacquire various types of biosignals including an EEG signal and an EMGsignal, and match them to detailed motion commands, thereby realizingdiverse and natural motions in virtual reality. A signal processingalgorithm for understanding the user's intention for each command andreducing the failure rate is the same as described above.

The avatar control unit 400 receives the determined command and controlsthe avatar to perform a motion corresponding to the command through theprocessor. The user's motion intention is converted to a state anddetermined as a command. (e.g., start 1, stop 2, turn left 3, turn right4, stand 5, etc.)

Even for the same motion, the magnitude of rotation and the movementspeed may be different, and in addition to the state of the command, maybe adjusted according to the amplitude of the biosignal. For example,when an EEG signal having a specific frequency or an EMG signalgenerated at a specific part is detected, and the signal of thecorresponding frequency and the corresponding part matches a “goforward” command, the avatar control unit 400 controls the avatar to goforward. In this instance, as the amplitude of the EEG signal or the EMGsignal is higher, the avatar may go forward at a faster speed, and asthe amplitude is lower, the avatar may go forward at a slower speed.

Different feedbacks may be provided for the same motion depending on theintensity of the biosignal and may be used in evaluating the user'sbiosignal characteristics or training for enhancing the user'sbiosignal.

The output unit 500 is an output device for outputting an image of theavatar performing the motion in real-time, for example, a TV, a monitor,and a head-mounted display (HMD). In an embodiment, the output unit 500may include a display with a light-emitting diode (LED), an organic LED(OLED), a light-emitting polymer (LEP), an electroluminescent (EL)device, a field-emission display (FED), or a polymer LED (PLED).

In an exemplary embodiment, the output unit 500 may be the HMD devicethat can be worn on the head. The HMD device is a next-generationdisplay device that is worn on the user's head and allows the user tosee images through displays corresponding to two eyes. In general, theinclusion of an IMU sensor makes it possible to synchronize the user'shead movement through a rotation value. Through this, the user can feelmore full immersion in an augmented reality or virtual realityenvironment than those when the user watches on the existing monitordevices.

As shown in FIG. 3 , the image of the avatar performing the motion maybe outputted in real-time. As shown, the user's avatar may perform amotion, for example, going forward or rotating to left or right,according to the control command. As the user watches the real-timeoutput image of the avatar performing the motion based on the biosignal,the user can obtain immediate feedback.

The protocol generating unit 600 generates a protocol that providespredetermined tasks that can be performed by controlling the motion ofthe avatar and determines if the avatar performed the predeterminedtasks. In an embodiment, the protocol includes an evaluation protocolfor evaluating the user's biosignal characteristics or a trainingprotocol for enhancing the user's biosignal.

The evaluation/training protocol as used herein refers to a program forvirtual training in a similar environment to a real motion in a virtualreality environment. Through the brain signal based motor imagery, it ispossible to improve the cognitive abilities of patients with mentalillness or motor abilities of patients with neurological impairment.These are improvements in brain function and motor function using thebiofeedback technique. In summary, behavior patterns may be regulated bysetting a target brainwave state, eye movement, and musclecontraction/relaxation and training the user for how to regulate inorder to reach the target brainwave state, and may iterate to improvecognitive and motor abilities.

In an embodiment, the evaluation protocol may instruct the user togenerate a specific biosignal, and measure and score the number of timesor intensity of the specific biosignal generated for a preset time.Alternatively, the evaluation protocol may evaluate and score theaccuracy of the motion of the avatar according to the biosignal.Inducing the avatar to move may give greater motivation to the user thandetecting and scoring the biosignal.

For example, the evaluation protocol may apply a sensory stimulus(visual, auditory, kinesthetic) to the user through the display toinduce the generation of a specific brainwave or instruct theapplication of a force to a specific muscle, and when the user generatesa biosignal in response, control the avatar according to the biosignal,and evaluate the characteristics of the biosignal by scoring theaccuracy of the motion performed by the avatar.

In an embodiment, the training protocol instructs the user to generate aspecific biosignal to control the avatar. For example, there may beprovided a training program that enhances the biosignal by outputting inreal-time images of the avatar being controlled by the biosignal tostimulate the user. The instruction motion of the avatar given by theprogram requires stepwise high-level motions, for example, running on apreset track, rotation and obstacle avoidance as shown in FIG. 3 toinduce gradual improvement in the user's ability to generate biosignals.With training, the user can activate brainwaves of desiredcharacteristics, and control the muscles of a desired body part orcontrol eye movements, leading to improvements in cognitive and motorabilities.

A Biosignal-Based Avatar Control Method

FIG. 4 is a flowchart showing a biosignal-based avatar control methodaccording to an embodiment. Each step (S10 to S70) shown in FIG. 4 isnot necessarily in a sequential or essential relationship. That is, somesteps may be omitted or performed in different orders.

Referring to FIG. 4 , first, the step of generating a user's avatar in avirtual reality environment is performed (S10). In an embodiment, theavatar may be automatically generated based on a measured biosignal. Forexample, the user's heartbeat change or face temperature change may bedetected and the avatar's facial color or expression and pose may bechanged accordingly, or the user's gaze direction or blink may bedetected by measuring an EOG signal and the avatar's gaze direction maybe represented accordingly. Appropriately changing the avatar's shape orattitude in a virtual environment according to the user's biosignal mayimprove realism and immersion in virtual reality.

Subsequently, the step of receiving the user's biosignal from a sensoris performed (S20). In an embodiment, the biosignal may include an EEGsignal, an EMG signal, and an EOG signal, and in addition to thebiosignals described herein, a variety of biosignals may be measured andused. The features and measuring methods of each biosignal are the sameas described above, and redundant descriptions are omitted herein.

Subsequently, the step of determining the user's command based on thebiosignal is performed (S30). In an embodiment, the step of determiningthe user's command based on the measured biosignal includes the step ofprocessing the measured biosignal through frequency filtering, spatialfiltering, feature selection and classification, and the step ofdetermining a command corresponding to a result value of the processing.Related information necessary to determine the command, for example, ananalysis algorithm or lookup table, may be stored in memory togetherwith a biosignal based control program.

According to embodiments, various types of commands may be pre-stored tomatch the biosignals. For example, further to a command for simplymoving the avatar forward, rearward, leftward and rightward, a commandsuch as sitting down/standing, or a joint-related movement such aslifting up and down the feet and bending or straightening the knees maybe designated as the command. As opposed to the existing gesture capturebased avatar control method, the present disclosure may simultaneouslyacquire various types of biosignals including an EEG signal and an EMGsignal, and match them to detailed motion commands, thereby realizingdiverse and natural motions in virtual reality.

Subsequently, the step of controlling the avatar to perform a motioncorresponding to the command is performed (S40). The user's motionintention is converted to a state and determined as a command (e.g.,start 1, stop 2, turn left 3, turn right 4, stand 5, etc.). Even for thesame motion, the extent and speed of the rotation may be different, andin addition to the state of the command, may be adjusted according tothe amplitude of the biosignal as described above. Different feedbacksmay be provided for the same motion depending on the intensity of thebiosignal and used in evaluating the characteristics of the user'sbiosignal or training for enhancing the user's biosignal.

Subsequently, the step of outputting an image of the avatar performingthe motion in real-time is performed (S50). The avatar's motion,training tasks, whether the tasks were performed and evaluation scoresmay be displayed together on an output device, for example, TV, amonitor, and the HMD. As shown in FIG. 3 , the image of the avatarperforming the motion may be outputted in real-time. As shown, theuser's avatar may perform a motion, for example, going forward orrotating to left or right, according to the control command, and whenseeing this, the user may obtain immediate feedback.

Subsequently, the step of providing predetermined tasks that can beperformed by controlling the avatar's motion (S60), and the step ofdetermining if the avatar performed the predetermined tasks (S70) areperformed. The protocol includes an evaluation protocol for evaluatingthe user's biosignal characteristics or a training protocol forenhancing the user's biosignal. The detailed description and examples ofthe evaluation/training protocol are the same as described above, andredundant descriptions are omitted herein.

The biosignal-based avatar control method according to an embodiment maybe implemented in the form of applications or program commands that canbe executed through various computer components and may be recorded incomputer-readable recording media. The computer-readable recording mediamay include program commands, data files, and data structures, alone orin combination.

The program commands recorded in the computer-readable recording mediamay be specially designed and configured for the present disclosure andmay be those known and available to those having ordinary skill in thefield of computer software.

Examples of the computer-readable recording media include hardwaredevices specially designed to store and execute program commands, forexample, magnetic media such as hard disk, floppy disk and magnetictape, optical media such as CD-ROM and DVD, magneto-optical media suchas floptical disk, and ROM, RAM and flash memory.

Examples of the program command include machine code generated by acompiler as well as high-level language code that can be executed by acomputer using an interpreter. The hardware device may be configured toact as one or more software modules to perform the processing accordingto the present disclosure, or vice versa.

According to the biosignal-based avatar control system and method asdescribed hereinabove, it is possible to provide feedback in real-timeby understanding the user's intention through measurement and analysisof biosignals such as EEG, EMG and EOG signals, and controlling theuser's avatar in a virtual reality environment based on the user'sintention.

In addition, the system according to an embodiment may provide theevaluation/training protocol for evaluating the user's biosignalcharacteristics or enhancing the user's biosignal by providingpredetermined tasks that can be performed by controlling the avatar'smovement, and determining if the avatar performed the predeterminedtasks. Through this biofeedback system, it is possible to improve theuser's brain function and motor function and obtain a long-termtreatment effect.

While the present disclosure has been hereinabove described withreference to the embodiments, those skilled in the art will understandthat various modifications and changes may be made thereto withoutdeparting from the spirit and scope of the present disclosure defined inthe appended claims.

What is claimed is:
 1. A biosignal-based avatar control system,comprising: an avatar generator that generates a user's avatar in avirtual reality environment; a biosignal measuring unit that measuresthe user's biosignal using a sensor; a command determining unit thatdetermines the user's command based on the measured biosignal; an avatarcontroller that controls the avatar to perform a motion corresponding tothe command; an output unit that outputs an image of the avatarperforming the motion in real-time; and a protocol generator thatgenerates a protocol for providing predetermined tasks that can beperformed by controlling the avatar's motion, and for determiningwhether the avatar has performed the predetermined tasks, wherein theprotocol includes: an evaluation protocol for evaluating the user'sbiosignal characteristics, or a training protocol for enhancing theuser's biosignal, and wherein the training protocol is configured toimprove the user's cognitive and motor abilities to enhance the user'sbiosignal that controls the avatar's motion to perform the predeterminedtasks.
 2. The biosignal-based avatar control system according to claim1, wherein the biosignal includes at least one of anelectroencephalogram (EEG) signal, an electromyogram (EMG) signal and anelectrooculogram (EOG) signal.
 3. The biosignal-based avatar controlsystem according to claim 1, wherein a speed of the motion or magnitudeof rotation of the avatar is controlled based on an amplitude of thebiosignal.
 4. The biosignal-based avatar control system according toclaim 1, wherein the command determining unit processes the measuredbiosignal through frequency filtering, spatial filtering, featureselection, and classification, and determines a command corresponding toa result value of the processing.
 5. The biosignal-based avatar controlsystem according to claim 1, wherein the evaluation protocol evaluatesthe user's biosignal characteristics based on a number of times orintensity of the user's biosignal generated for a preset time in orderto control the avatar's motion to perform the tasks.
 6. Thebiosignal-based avatar control system according to claim 1, wherein theevaluation protocol evaluates the user's biosignal characteristics basedon accuracy of the tasks performed by the avatar.
 7. The biosignal-basedavatar control system according to claim 1, wherein the trainingprotocol provides stepwise high-level tasks to induce gradualenhancement of the user's biosignal.
 8. A biosignal-based avatar controlmethod that is performed by a processor, the method comprising:generating a user's avatar in a virtual reality environment; receivingthe user's biosignal from a sensor; determining the user's command basedon the biosignal; controlling the avatar to perform a motioncorresponding to the command; outputting an image of the avatar forperforming the motion in real-time; and providing a protocol thatprovides predetermined tasks that can be performed by controlling theavatar's motion, and determines whether the avatar has performed thepredetermined tasks, wherein the protocol includes: an evaluationprotocol for evaluating the user's biosignal characteristics, or atraining protocol for enhancing the user's biosignal, and wherein thetraining protocol is configured to improve the user's cognitive andmotor abilities to enhance the user's biosignal that controls theavatar's motion to perform the predetermined tasks.
 9. Thebiosignal-based avatar control method according to claim 8, wherein thebiosignal includes at least one of an electroencephalogram (EEG) signal,an electromyogram (EMG) signal and an electrooculogram (EOG) signal. 10.The biosignal-based avatar control method according to claim 8, whereinthe determining the user's command based on the biosignal comprises:processing the biosignal through frequency filtering, spatial filtering,feature selection, and classification, and determining and executing acommand corresponding to a result value of the processing.
 11. Thebiosignal-based avatar control method according to claim 8, wherein aspeed of the motion or magnitude of rotation of the avatar is controlledbased on an amplitude of the biosignal.
 12. The biosignal-based avatarcontrol method according to claim 8, wherein the evaluation protocolevaluates the user's biosignal characteristics based on a number oftimes or intensity of the user's biosignal generated for a preset timein order to control the avatar's motion to perform the tasks.
 13. Thebiosignal-based avatar control method according to claim 8, wherein theevaluation protocol evaluates the user's biosignal characteristics basedon accuracy of the tasks performed by the avatar.
 14. Thebiosignal-based avatar control method according to claim 8, wherein thetraining protocol provides stepwise high-level tasks to induce gradualenhancement of the user's biosignal.
 15. A non-transitory computerreadable storage medium for storing therein a computer program forperforming the biosignal-based avatar control method according to claim8.